Timing relay



April 15, 1952 N. R. M. WEIBULL 2,592,986

TIMING RELAY Filed April 4, 1949 Patented Apr. 15, 1952 TIMING RELAY Nils R. M. Weibull, Malmo, Sweden Application April 4, 1949, Serial No. 85,300 In Sweden April 15, 1948 4 Claims.

This invention relates to an electric timing relay, i. e. an apparatus for breaking or closing an electric circuit after a certain adjustable time.

An embodiment of the invention is illustrated in the accompanying drawing showing a partly diagrammatic vertical elevation of the apparatus.

The principal parts of the apparatus are an electric or mechanical clockwork I, and a spindle 2 provided on part of its length with a screw thread 2a having a great pitch. Another part of the spindle length is formed into a long spindle spur gear 21). Between two stationary bearings 3 a nut wheel 4 driven by the clockwork I is mounted on the threaded portion of the spindle. This nut wheel 4 has a center hole with a screw thread that corresponds to the screw thread of the spindle. Another gear 5 meshes with the spindle spur gear it). An electromagnet 6 with an armature 6a is provided with a lever 1 attached to the armature. A brake shoe 8 and two or more mercury switches I3 are arranged on the said lever I. When current is supplied to the electromagnet t, the armature 6a is attracted and the brake shoe 8 is pressed against the periphery of the wheel 5 which is thereby braked and prevented from rotating. At the same time the switches 53 close (or break). A set screw 9, preferably with an appurtenant scale of adjustment, is arrangedto adjustably limit the movability of the spindle in one direction. A contact device IE3 including two contacts I I and I2 is so arranged that in a certain position the spindle 2 breaks the contact II and in another position closes the contact I2.

The threaded portion 2a of the spindle 2 has so steep a pitch that the spindle may be pressed axially through the nut wheel l independently of the rotation thereof. In other terms the thread is non-selflocking.

The operation of the apparatus is as follows. The wheel 4 is driven at a uniform speed by the clockwork i. The spindle 2 is held in contact with the set screw 9 either due to its own weight or due to spring pressure. The spindle 2 rotates together with the nut wheel 4 and the wheel 5 rotates, too. If current is supplied to the electromagnet E, the armature 6c is attracted and the brake shoe 8 is pressed against the wheel 5, whereby the latter is stopped. On account there of the spindle '2 ceases to rotate and performs an axial movement at constant speed, The time which the spindle needs for moving through the distance between its initial position determined by the set screw 9 and the position for operating the contacts I I and I2 of the contact device Ii),

is consequently proportional to said distance. The operating time of the timing relay is thus adjustable by means of the set screw 9.

The electric connections are such that the contact II breaks the current to the electromagnet 6. The armature 6a of this magnet then leaves the magnet due to its weight or due to a spring force, whereby the braking of the wheel 5 ceases and the spindle 2 returns to its initial position, either on account of its weight if the spindle axis is vertical, or by the action of a spring if the spindle is mounted horizontally or obliquely which makes the weight of the spindle insufficient as a returning force.

If the timing relay is started by actuation of a push button I 4 arranged for this purpose, which is customary, one of the switches I3 may be used as a holding contact for the electromagnet, so that the armature thereof remains attracted also after the actuation of the push button has ceased. Another switch I3 or several switches I3 may be used for connecting or disconnecting, during a certain adjustable time, the apparatus or apparatuses to be operated or controlled with the aid of the timing relay.

What I claim and desire to secure by Letters Patent is:

1. In a thning relay of the character described the combination comprising a rotatable and axially displaceable spindle having on part of its length a non-selflocking screw thread, two stationary bearings on said spindle, a nut wheel arrangedon said spindle in mesh with the nonselfiocking screw thread thereof and between said bearings, a clockwork for driving said nut wheel, a braking device including and operable by an electromagnet for preventing the spindle from rotation but not from moving axially, and a contact device operable by the spindle in a certain axial position thereof for controlling the circuit of said electromagnet.

2. In a timing relay as claimed in claim 1, a push button operated switch in the circuit of said electromagnet, a number of electric circuit controlling switches associated with and operable by said electromagnet, and at least one of the last-mentioned switches being a holding contact in the circuit of said electromagnet.

In a timing relay as claimed in claim 1, and adevice for adjusting the operating time of the timing relay, said device comprising an adjustable screw for limiting the axial displacement of the spindle in one direction opposite to that in which the spindle is to be axially displaced to operate the contact device operable by 3 the spindle, and the spindle being axially biassed REFERENCES CITED in said first-mentioned direction, so that the The following references are of record in the spindle, as soon as the braking thereof ceases, file of this patent. will be axially displaced in the direction towards said adjustable screw until stopped by the latter. 5 UNITED STATES PATENTS 4. In a timing relay as claimed in claim 1, and Number Name Date a long spur Wheel formed on another part of 1,801,129 Warren Apr. 14, 1931 the length of the spindle, and a gear in mesh 2,331,916 Kitroser Oct. 19, 1943 with said spur wheel, and the braking device being arranged for co-operating with said gear. 10

NILS R. M. WEIBULL. 

